Design, synthesis and antifungal activity of (E)-3-acyl-5-(methoxyimino)-1,5-dihydrobenzo[e][1,2]oxazepin-4(3H)-one analogues

Nitrogen- or oxygen-containing organic compounds which have significant antifungal activity, twenty one novel nitrogen or oxygen-containing (E)-3-acyl-5-(methoxyimino)-1,5-dihydrobenzo[e][1,2]oxazepin-4(3H)-one analogues were designed and synthesized, and their structures were confirmed by H-1 NMR, C-13 NMR and HRMS. Preliminary bioassay showed that most of them exhibited certain-to-good antifungal activity. Compounds 5k-2, 5n, 5p and 5r exhibited over 80% inhibitory rate against Sclerotinia sclerotiorum at 50 mu g/mL, and 5r exhibited good antifungal activity against S. sclerotiorum with EC50 of 7.21 mu g/mL. Compounds 5a and 5r also showed over 90% inhibition against Botrytis cinerea. In particular, 5r showed significant higher activity with the lowest EC50 of 7.92 mu g/mL than the positive control trifloxystrobin (21.96 mu g/mL) and azoxystrobin (9.43 mu g/mL). Graphic abstract Providing a practical method for the synthesis of new scaffolds 1,2-Benzoxazepinone and systematically investigate their antifungal activity.